1. Field of the Invention
The present invention relates to image forming apparatus.
2. Description of the Related Art
An image forming apparatus, such as an electrophotographic printer, copier, or facsimile machine, makes an image by forming an electrostatic latent image on a photosensitive drum with a laser, developing the latent image with a toner to provide a toner image, transferring the toner image from the photosensitive drum to a recording medium, and fixing the toner image onto the recording medium.
The main control unit of a printer, for example, reads the recording medium information from the recording unit and looks up the setting tables in the record unit to determine the printing conditions, such as the transfer voltage applied to the transfer roller for transferring the toner image to the recording medium from the photosensitive drum, the fixing voltage for supplying the minimum heat for requiring the fixing of the toner image, and the transportation speed of the recording medium for compensating the transfer voltage and the fixing voltage. See JP 2001-242742.
However, the number of types of recording mediums used in the printer is so large that the image quality of prints made with only the printing conditions recorded in the setting tables is not necessarily good. The optimal printing conditions vary with the type of recording medium so that the types of recording mediums that can provide a certain image quality with similar printing conditions are grouped together to make setting tables for a limited number of types of recording mediums. Consequently, the common printing conditions are used for a plurality of types of recording mediums so that the optimal image quality is not provided for a certain type of recording medium.